CN112740428A - Method and apparatus for detecting an open circuit condition in a piezoelectric element connection - Google Patents
Method and apparatus for detecting an open circuit condition in a piezoelectric element connection Download PDFInfo
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- CN112740428A CN112740428A CN201980060893.XA CN201980060893A CN112740428A CN 112740428 A CN112740428 A CN 112740428A CN 201980060893 A CN201980060893 A CN 201980060893A CN 112740428 A CN112740428 A CN 112740428A
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- 238000000034 method Methods 0.000 title claims abstract description 28
- 230000005284 excitation Effects 0.000 claims abstract description 53
- 238000012544 monitoring process Methods 0.000 claims abstract description 7
- 238000012360 testing method Methods 0.000 claims description 22
- 238000011156 evaluation Methods 0.000 claims description 4
- ORQBXQOJMQIAOY-UHFFFAOYSA-N nobelium Chemical compound [No] ORQBXQOJMQIAOY-UHFFFAOYSA-N 0.000 description 7
- 238000001514 detection method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000003990 capacitor Substances 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/54—Testing for continuity
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
- G01R31/282—Testing of electronic circuits specially adapted for particular applications not provided for elsewhere
- G01R31/2829—Testing of circuits in sensor or actuator systems
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/22—Measuring piezoelectric properties
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
- G01R31/2832—Specific tests of electronic circuits not provided for elsewhere
- G01R31/2836—Fault-finding or characterising
- G01R31/2839—Fault-finding or characterising using signal generators, power supplies or circuit analysers
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/80—Constructional details
- H10N30/802—Circuitry or processes for operating piezoelectric or electrostrictive devices not otherwise provided for, e.g. drive circuits
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- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Electromagnetism (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Tests Of Electronic Circuits (AREA)
Abstract
The proposed method for detecting an open state fault in a piezoelectric element connection comprises: exciting the piezoelectric element with an electrical excitation signal in the form of a pulse train, the frequency of said pulse train being selected such that the piezoelectric element acts as a low pass filter; and monitoring and evaluating the electrical output signal generated by the piezoelectric element in response to the excitation signal.
Description
Technical Field
The invention relates to a method for fault detection in a piezoelectric element.
Background
In the piezoelectric device, a failure such as an open state may occur. To avoid further damage to the device, faults in the piezoelectric element must be detected quickly. For this reason, devices for detecting faults in piezoelectric arrangements have been proposed (see for example US5376854, CN 105675960A).
Previous methods include exciting the piezoelectric element at its natural resonant frequency, monitoring the voltage generated by the piezoelectric element and evaluating the recorded voltage signal, as shown for example in US6639411B1 or US6870377B 2. The recorded signal is then compared to a prototype signal that has been recorded using a normally operating piezoelectric element using a similar input. The comparison of the two signals therefore relies on analyzing the excited ringing at a frequency at the resonant frequency of the transducer.
Fig. 1 shows an example of a voltage signal recorded with an open (i.e., failed) piezoelectric element or an open (i.e., working) piezoelectric element according to a conventional test method.
However, this known method for open circuit detection is prone to significant variations and is therefore not very reliable. A false open circuit detection will result in a well functioning sensor being replaced.
Disclosure of Invention
The object of the present invention is to overcome the problems of the prior art solutions, in particular the lack of reliability when detecting an open circuit of a piezoelectric element. This object is solved by the subject matter of the independent claims. While previous methods relied on analyzing the ringing of the excitation, the present invention is based on directly observing the excitation itself. This avoids the effects of environmental effects such as propagation in a medium (e.g. liquid or air) or temperature. Furthermore, the present invention uses excitation with a high frequency pulse train instead of the resonant frequency of the piezoelectric element used in the previous method. This results in the piezoelectric transducer acting as a low pass filter. The electrical output signal generated by the piezoelectric element in response to the excitation signal as a voltage signal is monitored and evaluated only during the excitation.
To avoid problems due to small measurement errors occurring in practical situations, the constant epsilon is defined as the excitation signal only in the interval Vmin,Vmin+ε]Or [ V ]max–ε,Vmax]Minimum number of internal values, where VminAnd VmaxRespectively the minimum and maximum value of the excitation signal. Alternatively, the constant ε may also be defined as the slave test circuit in a pretestThe output signal recorded with the piezoelectric element removed is only in the interval Vmin,Vmin+ε]Or [ V ]max–ε,Vmax]Minimum number of internal values, where VminAnd VmaxRespectively a minimum value and a maximum value of the output signal.
Typically, the frequency of the pulse train and the constant V are determined empirically over a plurality of test runsmin、VmaxAnd ε, thereby satisfying the above requirements. Thus, the test run is repeated until the frequency of the pulse train and the constant V occurmin、VmaxThe probability that the value of sum ε is more extreme than the corresponding values from all previous runs is less than a predetermined value, e.g., p ≦ 0.01.
The evaluation of the output signal generated by the piezoelectric element comprises: the monitored electrical output signal is compared to a characteristic indicative of the electrical signal generated by a properly functioning piezoelectric element. An example of a necessary and sufficient condition to classify the piezo element connection as normal operation is that the output signal is outside the vicinity of the minimum and maximum values of the pulse train]Vmin+ε,Vmax- ε [ takes a number of values. Alternatively, another example of a necessary and sufficient condition to classify the piezo element connection as normal operation is that the excitation signal is above VminVariance of all values of + epsilon and higher than V of output signalminThe variance of all values of + epsilon are significantly different. Thus, a significance level for classifying the piezoelectric element connections as functioning properly is empirically determined such that the number of significant differences and insignificant differences matches the desired reliability.
To perform the above method, a test apparatus for detecting an open state fault in the connection of piezoelectric elements is used. The apparatus comprises: an excitation unit operable to excite the piezoelectric element with an electrical excitation signal, wherein the excitation signal is a pulse train, wherein a frequency of the pulse train is selected such that the piezoelectric element acts as a low pass filter; a monitoring and evaluation unit operable to monitor and evaluate the electrical output signal generated by the piezoelectric element in response to the excitation signal. The monitoring unit is activated only when the excitation unit is active.
The test device with the piezoelectric element may be integrated in an electronic apparatus, wherein the electronic apparatus triggers a test operation of the test device, for example when the apparatus is started, to ensure that the piezoelectric element is functioning properly.
Drawings
The accompanying drawings are incorporated in and form a part of the specification to illustrate various embodiments of the present invention. Together with the description, the drawings serve to explain the principles of the invention. The drawings are only for purposes of illustrating preferred and alternative examples of how the invention may be made and used and are not to be construed as limiting the invention to only the embodiments shown and described. Furthermore, aspects of the embodiments can be formed separately or in different combinations-a solution according to the invention. Further features and advantages will become apparent from the following more particular description of various embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same elements, and in which:
FIG. 1 shows recorded voltage signals according to a known method for detecting whether a circuit in a piezoelectric device is open (FIG. 1A) or not open (FIG. 1B);
FIG. 2 shows recorded voltage signals for a method according to the present invention for detecting whether a circuit in a piezoelectric device is open (FIG. 2A) or not open (FIG. 2B);
FIG. 3 illustrates a test circuit for detecting an open circuit of a piezoelectric element connection according to the present invention;
FIG. 4 shows a flow chart of a method according to a first embodiment of the invention;
fig. 5 shows the recorded voltage signals for the method according to the invention for detecting whether the electrical circuit in the piezoelectric device is open (fig. 5A) or not open (fig. 5B).
Detailed Description
The following examples are intended to illustrate the invention for a better understanding. They do not limit the scope of the claims.
As shown in fig. 2, the voltage signals in the present invention can be easily and reliably distinguished compared to the previous method shown in fig. 1. When open, the piezoelectric element has no effect on the signal recorded during excitation. The recorded signal is therefore equal to the original pulse train used to excite the piezoelectric element. This means that the sample can only take two values, 0V or the maximum voltage of the pulse. When the circuit is not open, the piezoelectric element acts as a low pass filter, thus affecting the signal recorded during excitation. This means that the samples take values above 0V and below the maximum voltage of the pulse. By counting the samples at a value between 0V and the maximum voltage, the open state can be reliably distinguished from the non-open state.
According to an advantageous embodiment of the present invention, a method for detecting an open state fault in a piezoelectric element connection is provided. The test apparatus includes a piezoelectric element 102, a resistor 106, an inductor 108, and a voltage source 104 connected in series. Using the voltage source 104, the piezoelectric element can be excited with an excitation signal. Further, the voltmeter 100 is connected in parallel with the piezoelectric element 102, the resistor 106, and the inductor 108. Using this voltmeter 100, an output signal generated by the piezoelectric element 102 in response to the excitation signal can be measured. Fig. 3 shows the test apparatus in circuit form. The test method according to the first embodiment is outlined in the form of a flow chart in fig. 4.
Specifically, to test whether an open-state fault exists, the piezoelectric element 100 is excited with an electrical excitation signal. The excitation signal is a pulse train. By definition, a burst contains only two values, the minimum value Vmin(usually 0V) and a maximum value Vmax. This means that the excitation signal is only in the vicinity of the minimum value Vmin,Vmin+ε]And the vicinity of the maximum value [ V ]max–ε,Vmax]Value, where ε is the excitation signal only in the interval [ V ]min,Vmin+ε]Or [ V ]max–ε,Vmax]The smallest non-negative real number of the inner value. The constant epsilon is introduced to ensure that the excitation signal is in the interval even if measurement errors occur]Vmin+ε,VmaxNor does it take any value within-epsilon. This is an important characteristic that will help to distinguish between open and non-open states.
The frequency of the excitation signal is chosen to be much higher than the resonant frequency of the piezoelectric element 102. In particular, the frequency is chosen to be sufficiently high that the piezoelectric element 102 is no longer able to follow the excitation signal and therefore acts as a low-pass filter. This means that if the piezoelectric element 102 is active, it modifies the excitation signal such that the output signal is significantly different from the excitation signal. In contrast, when an open-circuit fault occurs, the piezoelectric element 102 has no influence on the excitation signal, and thus the output signal is similar to the excitation signal. This characteristic will help to distinguish between open and non-open states.
Previous methods for detecting an open circuit condition recorded the output signal for further analysis both during excitation and during subsequent ringing. A disadvantage of this approach is that environmental effects, such as propagation in a medium (e.g. liquid or air) or temperature, can affect the output signal during ringing, thereby distorting the comparison of the excitation signal and the output signal. To avoid this effect, the present embodiment records the output signal only during excitation (and not ringing).
When the recording of the output signal is finished, the recorded output signal must be analyzed to determine whether there is an open fault in the connection of the piezoelectric element. Fig. 2 includes two graphs, the upper one showing an example of an output signal that would occur with an open circuit condition, and the lower one showing an example of an output signal that would occur without an open circuit condition. To better understand how the two output signals are distinguished from each other, reference is made to fig. 5, wherein the connecting lines between adjacent samples are omitted in fig. 5A. In this figure, the difference between the two signals is apparent.
In the case of an open state, the excitation signal is not modified by the piezoelectric element, and thus the output signal is similar to the excitation signal. According to Vmin、VmaxAnd e, the excitation signal is only in the interval Vmin,Vmin+ε]Or [ V ]max–ε,Vmax]Taking the value in the step (1). This is true for the output signal, since it is similar to the stimulus signal. In the case of a non-open state, the excitation signal is modified by a series connection of a piezoelectric element, a resistor and an inductor. The signal is attenuated by the resistor and inductor and low pass filtered by the piezoelectric element. Thus, the output signal has a lower amplitude and a different shape than the excitation signal. This characteristicCan be used to distinguish between open and non-open states. When the output signal contains a value within a range]Vmin+ε,VmaxA large number of samples in ε, the piezoelectric element connection is considered to be in an unopened state.
The second embodiment is the same as the first embodiment with one exception: in the first embodiment, the criterion that the circuit state is not disconnected is that the output signal contains a value in an interval]Vmin+ε,Vmax-a number of samples in ε [ s ]. In contrast, in the second embodiment, the criteria for the circuit state not to be opened are: of the output signal having a value greater than VminThe variance of the samples at the value of + epsilon significantly exceeds that of the excitation signal having a value greater than VminThe variance of the samples for the value of + epsilon.
The third embodiment is the same as the first embodiment with one exception: in the first embodiment of the present invention,
selection of Vmin、VmaxAnd epsilon so that VminAnd VmaxRespectively minimum and maximum values of the excitation signal, and epsilon is the excitation signal only in the interval Vmin,Vmin+ε]Or [ V ]max–ε,Vmax]The minimum number of internal values.
In contrast, in the third embodiment, the constant ∈ is defined such that the output signal that has been recorded in the case where the piezoelectric element is removed from the test circuit in the pretest is only in the section [ V [ ]min,Vmin+ε]Or [ V ]max–ε,Vmax]Minimum number of internal values, where VminAnd VmaxRespectively a minimum value and a maximum value of the output signal.
Defining V using an output signal of a test circuit having an open statemin、VmaxAnd epsilon has the advantage that the path of the output signal is similar to the path of the output signal in the non-open state, whereas the stimulus signal is directly available without passing through the path.
List of reference numerals
100 output signal
102 piezoelectric element
104 voltage source
106 resistor R1
108 inductor L1
110 capacitor C1
112 capacitor C2
114 resistor R2
116 inductor L2
Claims (14)
1. A method for detecting an open state fault in a piezoelectric element connection, the method comprising:
the piezoelectric element (102) is excited with an electrical excitation signal,
wherein the excitation signal is a pulse train,
wherein the frequency of the pulse train is selected such that the piezoelectric element (102) acts as a low-pass filter;
monitoring and evaluating an electrical output signal (100) generated by the piezoelectric element (102) in response to the excitation signal.
2. The method of claim 1, wherein the electrical output signal (100) generated by the piezoelectric element (102) is a voltage signal.
3. The method according to claim 1 or 2, wherein the electrical output signal (100) generated by the piezoelectric element is monitored only during excitation.
4. A method according to claim 3, wherein the constant epsilon is defined such that the excitation signal is only in the interval [ V [ ]min,Vmin+ε]Or [ V ]max–ε,Vmax]Minimum number of internal values, wherein VminAnd VmaxRespectively the minimum and maximum value of the excitation signal.
5. A method according to claim 3, wherein the constant s is defined as the output signal that has been recorded with the piezoelectric element removed from the test circuit in the calibration step only in said interval [ V [ ]min,Vmin+ε]Or [ V ]max–ε,Vmax]Minimum number of internal values, wherein VminAnd VmaxAre respectively the most of the output signalsSmall and maximum values.
6. The method of any preceding claim, wherein the frequency of the pulse train and the constant V are determined empirically over a plurality of test runsmin、VmaxAnd ε.
7. The method of claim 6, wherein the test run is repeated until the frequency of the pulse train occurs and a constant Vmin、VmaxAnd the probability that the value of e is more extreme than the corresponding values from all previous runs is less than a predetermined value.
8. The method of any one of the preceding claims, wherein the evaluation of the output signal generated by the piezoelectric element comprises: the monitored electrical output signal is compared to a characteristic indicative of the electrical signal generated by a properly functioning piezoelectric element.
9. A method according to claim 4 or 5, wherein a necessary and sufficient condition for classifying a piezo-element connection as normal operation is that the output signal is outside the vicinity of the minimum and maximum values of the pulse train]Vmin+ε,Vmax- ε [ takes a number of values.
10. A method according to claim 4 or 5, wherein a necessary and sufficient condition to classify a piezo-element connection as normal operation is that the excitation signal is above VminThe variance of all values of + epsilon and of the output signal above VminThe variance of all values of + epsilon are significantly different.
11. The method of claim 8 or 9, wherein the level of significance for classifying the piezoelectric element connections as functioning properly is determined empirically such that the amount of significant and insignificant difference matches the desired reliability.
12. A test apparatus for detecting an open circuit condition fault in a piezoelectric element connection, the apparatus comprising:
an excitation unit connectable to a piezoelectric element (102) to be tested and operable to excite the piezoelectric element (102) with an electrical excitation signal,
wherein the excitation signal is a pulse train,
wherein the frequency of the pulse train is selected such that the piezoelectric element (102) acts as a low-pass filter;
a monitoring and evaluation unit operable to monitor and evaluate the electrical output signal generated by the piezoelectric element in response to the excitation signal.
13. The test device of claim 12, wherein the monitoring unit is activated only when the excitation unit is activated.
14. The test device according to claim 12 or 13, wherein the test device with the piezoelectric element is integrated in an electronic apparatus, wherein the electronic apparatus triggers a test run of the test device.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP18195891.9 | 2018-09-21 | ||
| EP18195891.9A EP3627574B1 (en) | 2018-09-21 | 2018-09-21 | Method and apparatus for detecting an open circuit state in a piezoelectric element connection |
| PCT/EP2019/075202 WO2020058420A1 (en) | 2018-09-21 | 2019-09-19 | Method and apparatus for detecting an open circuit state in a piezoelectric element connection |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112740428A true CN112740428A (en) | 2021-04-30 |
| CN112740428B CN112740428B (en) | 2024-07-19 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201980060893.XA Active CN112740428B (en) | 2018-09-21 | 2019-09-19 | Method and apparatus for detecting open state in piezoelectric element connection |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US11300607B2 (en) |
| EP (1) | EP3627574B1 (en) |
| CN (1) | CN112740428B (en) |
| WO (1) | WO2020058420A1 (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06255134A (en) * | 1991-09-20 | 1994-09-13 | Pfu Ltd | Abnormality detection device of piezoelectric element |
| US20010039484A1 (en) * | 1998-09-30 | 2001-11-08 | Hellmut Freudenberg | Method and configuration for diagnosis of a capacitive actuator |
| CN1549929A (en) * | 2001-08-27 | 2004-11-24 | ��˹�ɵ¹�˾ | Diagnostics for piezoelectric sensor |
| CN105522238A (en) * | 2014-10-28 | 2016-04-27 | 佛山科学技术学院 | Discharging gap state detection module based on pulse sequence analysis |
| CN105675960A (en) * | 2016-02-19 | 2016-06-15 | 中国科学院力学研究所 | Apparatus and method for measuring open-circuit voltage of piezoelectric device |
| CN105891907A (en) * | 2016-04-12 | 2016-08-24 | 天津科技大学 | Portable piezoelectric detector multi-parameter testing system and testing method |
| CN107132447A (en) * | 2017-07-06 | 2017-09-05 | 国网四川省电力公司内江供电公司 | SVG power cell self checking methods |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT393416B (en) * | 1989-04-27 | 1991-10-25 | Avl Verbrennungskraft Messtech | MEASURING METHOD FOR DETERMINATION OR MONITORING OF MECHANICAL AND / OR PHYSICAL SIZES |
| JPH04286657A (en) | 1991-03-18 | 1992-10-12 | Fujitsu Ltd | Circuit for detecting abnormality of piezoelectric element |
| JPH10327586A (en) * | 1997-05-26 | 1998-12-08 | Chichibu Onoda Cement Corp | Circuit and method for controlling piezoelectric transformer |
| US6639411B1 (en) | 2000-09-05 | 2003-10-28 | Hutchinson Technology Incorporated | Microactuated suspension motor failure detection system |
| DE10325446B3 (en) * | 2003-06-05 | 2005-03-03 | Robert Bosch Gmbh | Method for detecting a fault in a piezoelectric actuator and drive circuit for a piezoelectric actuator, and piezoelectric actuator system |
| JP5274803B2 (en) * | 2006-09-27 | 2013-08-28 | シチズンホールディングス株式会社 | Oscillator and vibration gyro |
| EP2048343A1 (en) * | 2007-10-11 | 2009-04-15 | Delphi Technologies, Inc. | Detection of faults in an injector arrangement |
| DE102008001971A1 (en) * | 2008-05-26 | 2009-12-03 | Robert Bosch Gmbh | Method for diagnosing a load drop |
| US8401820B2 (en) * | 2008-10-03 | 2013-03-19 | United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | In situ health monitoring of piezoelectric sensors |
| US9857405B2 (en) * | 2012-11-06 | 2018-01-02 | Newport Corporation | System and method for detecting the presence and type of capacitive loads |
-
2018
- 2018-09-21 EP EP18195891.9A patent/EP3627574B1/en active Active
-
2019
- 2019-09-19 CN CN201980060893.XA patent/CN112740428B/en active Active
- 2019-09-19 WO PCT/EP2019/075202 patent/WO2020058420A1/en active Application Filing
-
2021
- 2021-03-18 US US17/205,527 patent/US11300607B2/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06255134A (en) * | 1991-09-20 | 1994-09-13 | Pfu Ltd | Abnormality detection device of piezoelectric element |
| US20010039484A1 (en) * | 1998-09-30 | 2001-11-08 | Hellmut Freudenberg | Method and configuration for diagnosis of a capacitive actuator |
| CN1549929A (en) * | 2001-08-27 | 2004-11-24 | ��˹�ɵ¹�˾ | Diagnostics for piezoelectric sensor |
| CN105522238A (en) * | 2014-10-28 | 2016-04-27 | 佛山科学技术学院 | Discharging gap state detection module based on pulse sequence analysis |
| CN105675960A (en) * | 2016-02-19 | 2016-06-15 | 中国科学院力学研究所 | Apparatus and method for measuring open-circuit voltage of piezoelectric device |
| CN105891907A (en) * | 2016-04-12 | 2016-08-24 | 天津科技大学 | Portable piezoelectric detector multi-parameter testing system and testing method |
| CN107132447A (en) * | 2017-07-06 | 2017-09-05 | 国网四川省电力公司内江供电公司 | SVG power cell self checking methods |
Also Published As
| Publication number | Publication date |
|---|---|
| US20210208192A1 (en) | 2021-07-08 |
| EP3627574B1 (en) | 2021-02-17 |
| WO2020058420A1 (en) | 2020-03-26 |
| US11300607B2 (en) | 2022-04-12 |
| EP3627574A1 (en) | 2020-03-25 |
| CN112740428B (en) | 2024-07-19 |
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